Exam Review

Intersecting- two lines that intersect  (cross) at any point.

Perpendicular- two lines that meet at a 90 degree angle.

Parallel Lines- two lines on a same plane that never meet.

Angle Bisector- a line that divides an angle into two equal parts.

Perpendicular Bisector- a line that bisects a different line segment.

Exam Review

Mean- add up all values divide by how many values there are.
eg: 6 + 4 + 8 = 18
     18  ÷ 3 = 6 
     the mean is 6.
Median- the middle number in a set of ordered values, might be the mean of 2 middle values. 
eg: the median of 2,5,6,8,9 is 6.
Mode- the value that shows up the most.
eg: the mode of  3,5,7,7, is 7.
Range- positive difference between largest and smallest values.
eg: the range of 4,8,5,6,9,1,3,5,8,6
                                  1,3,4,5,5,6,6,8,8,9  is  9-1=8
Outlier- value that are too big or too small compared to the other values.
eg: 3,8,4,5,9,33,5,6
       3,4,5,5,6,8,9,33 3 and 33


*always arrange the numbers from least to greatest*

Exam Review

Integers
 Negative numbers represents values below zero and positive numbers represent values above zero.
eg: above and below ground or sea level
1+(-2)=(-1) is an addition statement
3-(-1)=4 is  a subtraction statement


Opposite integers have the same numeral but different sign. 
eg: 3 and (-3)


(+) + (+) =
(-) - (-) =
(+) + (-) =
(-) + (+) =


(+) - (+) =
(-) - (-) =
(+) - (-) =
(-) -(+) =

Exam Review

Circle Formulas

c =  π  d
 c = 2  π r 
 d = 2r
 A=  π r2

*Area is the measure of space a two dimensional shape covers.

Exam Review

Transformations

translation- slide along a straight line.

rotation- turn about a fixed point.

reflection- mirror image.

Value and Constant

Value- a known or calculated amount.

Constant- a number that does not change and it increases or decreases the value of an expression.

Variable

Variable- a letter that represents an unknown number.

eg.

t, x, n, a

Expression

Expression- any single number or variable, or combination of operations

(-,+, ÷,x) involving numbers and variable.

eg.

5, n, 8t, x + 1, 2y - 7

Numerical Coefficient

Numerical Coefficient- a number that multiples the variable.

eg. 2t

2 <--- Numerical

t <--- Variable

Math Question

A group of students are talking, 2 friends leave the group.

Write an expression for the number of students in the group after the 2 leave.

Answer:

S-2

"S" because a group of students doesn't tell us how many are in the group.

S-2 because 2 friends leave the group.

"S" stands for Students

Common Denominator

Common denominator- a common multiple of the denominators of a set of fractions.

eg. a common denominator for 1/4 and 1/6 is 12.

4- 4,8,12,16,20
6- 6,12,18,24,30

Because a common multiple of 4 and 6 is 12.

Multiple

Multiple- the product of any given number and natural number like 1,2,3...

eg. some multiples of 3 are:
3,6,9,12,15,18...

Multiple is just skip counting.

Divisibility Rules for 6

If the number is divisible by 2 and 3 it is divisible by 6. (2x3=6)

EXAMPLE:

6396396=42=6 YES

4269951=33 NO

• Any number should be divisible by 2 and 3.
• Not just 2 and not just 3.
• Both 2 and 3.
• Last number should be even number.

Chapter 4 Review: 146-147

Question 4

Find 50% of 98

Use a ratio table.

50% of 98 is 49.

Whatever you do on one side, you do to the other side.

Order of Operations

B- Brackets

E- Exponents

D- Division or

M- Multiplication

A- Addition or

S- Subtraction

Step 1- First look for BRACKETS.

Step 2- Look for EXPONENTS.

Step 3- Look for DIVISION or MULTIPLICATION. (look from left to right)

Step 4- Look for ADDITION or SUBTRACTION. (look from left to right)